I USED to melt lead off brass fittings with a blow torch.” This is almost the first thing Mark Thomas says to me. Five minutes into my conversation with the stand-up comedian, author, activist (some would say irritant), former TV face and now actor and we are already deep into childhood.

“We used to go to the scrapyard around about tax bill time,” he continues. “The scrap yard was cash.

“My dad’s one bit of advice was, ‘Be back here in half an hour and don’t climb into fridges.’ Because if you lock yourself in a fridge you’re dead. But I just remember it being a place of wonder. The scrapyard was really exciting.

“So childhood was full of these weird adventures. We went once, right, and the car crush was on fire. The car crush was on fire! And my dad said, ‘What the f*** happened here?’ And the bloke’s got a cup of tea and a fag. He goes, ‘Well, what happened was, someone didn’t drain the petrol out of the tank properly and the whole thing goes and there’s nothing you can do. It’s hydraulics.

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“You just have to wait till it goes out. You call the fire brigade, you get yourself a cup of tea and a fag.’ “And my dad said, ‘How often does this happen?’ And the bloke said, ‘Every time I’ve got a f****** hangover.’ That was word for word.

“So, that sense of ... the world is there, grab what you can out of it, was absolutely inherent within my childhood. Every little bit you f****** took.”

At this point it seems worth telling you we are only halfway through an answer. The rest will take in his father, the prison officers he’s met during the run of his current play England & Son (the reason for our conversation) and the audience members who have come up to him after performances to talk about their own stories of addiction. All of this before I get to ask him another question.

Thomas has taken time out from making his mum some lunch to talk to me about the origin of this one-man play about life on the margins, written especially for him by playwright Ed Edwards.

Thomas has been touring it around the country since its Fringe debut in the summer. He is bringing it back to Edinburgh this week.

But I’ve interrupted him. On you go, Mark.

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“My dad was an incredibly violent man who had an incredibly awful upbringing and it translated into us. I’m not doing a ‘poor me’ or any of that. It’s just that that’s what it was.

“And Ed’s upbringing, his dad was military. So, a lot of the stories in the play are from me and a lot of the stories are from Ed. But there are other stories from people Ed’s known in his life and that I’ve known in my life.

The Herald: Comedian Mark ThomasComedian Mark Thomas (Image: Steve Ullathorne)

“Each night I get people coming up to me and chatting to me afterwards who are in recovery, or people who are trying to get into recovery. I was half an hour with a kid on Benzies in Manchester whose mate was standing next to him going, ‘You’ve got to come to the meeting.’”

He pauses, then sums up. “These are meaningful exchanges happening. We get people who work in prisons. We get probation officers. We get people who work in child protection, people who have been in care coming up to talk to us. And it sparks something bigger than the play. It’s been this monumental adventure.”

To talk to Mark Thomas is to be flung into the middle of a whirling ball of (often sweary) energy. It is rather exhilarating.

It is the same energy that powers his stand-up shows and which he now brings to the stage during England & Son.

Edwards’s play is both the story of a juvenile offender and an exploration of the crimes of colonialism.

That’s a lot to pack into an hour (an opening monologue that details Thomas and Edwards’s work with recovering addicts also has the same intensity and humour), but Thomas’s full-tilt performance energised the whole evening when I saw the play at the Tron in Glasgow in September.

This is the first time Thomas has acted in something he’s not written himself. On this evidence, he should do more of it.

“I am tempted to do more. I’ve really enjoyed it,” he admits, but he is also maybe ever-so slightly annoyed that people should be surprised that he’s quite good at it.

“The thing is I regard myself as a creative artist; whether it’s stand-up, whether it’s theatre shows that I’ve devised, whether it’s the books.

“I’m in the Guinness Book of Records for the most political demonstrations in 24 hours. And then a legal challenge which results in the law being changed. All of that is creative. The event becomes creative.

“It’s just that I’ve done a bit of acting now and people go, ‘Oh, Mark can do a bit of acting.’”

Ah yes, if he’s known for anything Thomas is known for his stand-up and his activism, often in tandem.

Between 1996 and 2003 he was a regular on Channel 4 with The Mark Thomas Comedy Product in which he took on (and took the hand out of) various politicians, corporations, arms dealers and the Indonesian army. (Wikipedia sums up one episode of the series with the piquant phrase, “phones Tory party central office and upsets them”.) But it’s been some time since he’s turned up on our TV screens. Is he done with TV or is TV done with him?

“Somebody asked me that the other day. Dorothy Byrne who used to be head of current affairs at Channel 4. We were at this film thing in Amsterdam.

“She introduced me to all these grand and great people and then she said, ‘So, Mark, did you tell telly to f*** off or did telly tell you to f*** off?’ I said, ‘In fairness, it was both.’”

He has no regrets. “What’s the point of doing television if only to stay on television? That way lies madness. You go on, you want to do something, you do it and then you stop it.”

He’s not missing the small screen. Thomas has a new love now. Speak to him and it’s clear that he adores the immediacy and energy of being on stage.

“What is great about theatre is you have this incredible capacity to play,” he suggests.

“What is brilliant about this show for me is that you can put an emotion out there and you can see it going through the audience. You want to move people beyond passive spectating into being emotionally engaged and involved with it.”

England & Son is a political play. That should surprise no-one. The tagline is “a nation that devours others will devour itself”. Is that where we are now, Mark?

“This nation has hollowed itself out. We are this hollow nation. Every time you turn on a tap you’re paying a tithe to someone in China. Every time someone goes in the sea you are swimming in the effluent that’s benefited someone in a multinational hedge fund.

“Every time you get on a train it’s helping nationalised railways in France. Everything has been hollowed out to help this small narrow band of class warriors in the Tory Party and their mates.

“We’ve eaten ourselves whole and there’s f*** all left. And Starmer is pointless … pointless.”

So where does Thomas find hope?

“I find the hope in ordinary people who want to change things so they organise things. Grassroots organising, whether it’s trade unions, whether it’s communities organising.”

He tells me another story because it’s what he’s good at, on stage and in conversation.

“I did a benefit down in Brighton in a place called Whitehawk, which is a s***hole estate. The Whitehawk is a community-owned football team and they have a trans chairperson. They have ‘no sexism, no racism, no transphobia, no homophobia’ all written out on the steps as you go into the stadium and it’s the chant of the fans.

“And they’ve had a voluntary ban on swearing to increase families coming to the game. And they all get their keys out during the key moments and go ‘Key moment’.

“That football club works with a food bank that does 400 meals a day; 400 meals a day for that estate. They shouldn’t be having to do it but they have.”

There’s hope in that, he says.

I have to ask, Mark, were you OK with the no swearing ban?

“I’ll be honest with you. I didn’t watch the match.”

England & Son opens at the Traverse Theatre, Edinburgh on Tuesday and runs until Saturday